Summary and Info
This book does a very good job of describing the decision making processes that go into using a particular piece of technology with Flex and how they apply this to their application which is actually titled "Rich Media X" (a blog/forum/user group app). If you want to see how or if you can integrate Drupal and Flex, this is probably a pretty good book. If you are looking for a book on a particular Flex framework like Cairngorm or what have you, it is not.
What I think people are finding deceptive about this book is the "Flex Application Development", the AdvancED label, and the idea that you will be able to layout a Flex application from start to finish (and you will, just most likely not the application you had in mind).
This book I see as being a great book to understand what is possible with Flex. I do not see this as a great book to learn Flex coding practices, coding frameworks, and anything else one might assume would be present in something titled Flex Application Development.
If you go into this looking for meat and potatoes and coming away from this book full of Flex YOU WILL be disappointed. 5 stars for what it covers well, but take 1 star away for hungering for more.